Ilona sits next to 3 phonetic neighbors — Elena, Ilana, and Alona are the closest matches by sound. Most share Ilona's German-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"bright, shining light"
"noble dwelling, noble refuge"
"lurking rock, murmuring rock"
"whole, universal"
"work, industriousness, striving"
"little cat (pet name)"
"home ruler; powerful in work"
"noble, nobility"
"noble, of noble kind"
"God is my oath"
"God has remembered (form of Zacharias)"
"eye, mirror"
"noble, of noble kind"
"powerful ruler"
"helmet, protection"
"lily flower"
"industrious, hardworking"
"reddish-brown dye plant"
Similar sound: These names share phonetic patterns with Ilona — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek via Hungarian origins, giving them the same cultural heritage as Ilona.
Rhythm: Ilona is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.